7 ms·

Making Ocean Water Drinkable

75 points by prawn 11y ago

ssaddi 11y ago
Very interesting article ... namely because fresh drinking water is now becoming a valuable resource. I'm sure the time the article has been written, better and more efficient ways would turn up for churning out fresh water for public consumption.
- soft_dev_person 11y ago
  I feel a very American point of view in your comment. Hasn't fresh drinking water been a valuable resource in plenty of places in the world for as long as time can remember?
  - TimeToTroll 11y ago
    I'm not sure if you've heard of Africa? I don't think there's any water down there.
  - nacnud 11y ago
    Not necessarily American; fresh drinking water is becoming scarcer across the world [1] and therefore even more valuable. [1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727435/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727435/
  - TheSpiceIsLife 11y ago
    Two years ago I moved from South Australia to Tasmania. South Australia is known as "driest state in the driest inhabited continent in the world"[1]. Here in Tasmania there's water oozing out of the side of the hills, I'm still amazed by it. 1. http://guides.slsa.sa.gov.au/water http://guides.slsa.sa.gov.au/water Someone else has usually put it better, this time I'll draw on user adrusi: ___________ https://news.ycombinator.com/item?id=8995524 https://news.ycombinator.com/item?id=8995524 The problem with freshwater is not that the global supply is limited, rather that supplies in some high-population areas are. The Amazon river sends 209,000 cubic meters into the Atlantic every second[1]. That's 18,100,000,000 per day. A single human drinks about two liters (0.02 cubic meters) every day. There are 7 billion humans, so the global requirement is 140,000,000 cubic meters of water. The Amazon alone contains 130 times more than the global requirement for drinking water. This is domestic consumption, which comprises 10% of water usage[2]. That means that 13 times more water flows through the Amazon than all of humanity uses. That's just one river. [1]: https://en.wikipedia.org/wiki/Amazon_River https://en.wikipedia.org/wiki/Amazon_River [2]: http://www.lenntech.com/water-food-agriculture.htm http://www.lenntech.com/water-food-agriculture.htm ___________
    - soft_dev_person 11y ago
      Clearly. I was just considering the drought in the west of US lately and the statement "is now becoming". Personally I live in Norway where we wash our garbage and shower in high quality drinking water. I still find it absurd from time to time, considering the lack of fresh water in many places in the world. Edit: Corrected quote
      - Swizec 11y ago
        We've got a similar situation going on in Slovenia. I don't know if we have more fresh water than Norway, or not, but there are towns that get 3meters of rainfall per year. One such town has an area of 25km^2, that's 25,000,000 square meters. Which means that on an average year, 75,000,000 cubic meters of fresh drinkable water fall from the sky. Comparing that to stats in the grandparent post: 14 times as much drinking water falls on a tiny town in a tiny European country, as the whole world needs for drinking. That's crazy.
        computator 11y ago
        Somewhere in your calculation there's an error. 75,000,000 cubic meters of fresh drinkable water fall from the sky per year divided by ( 0.002 cubic meters of drinking water needed per person per day x 365 days in a year ) = 103,000,000 people quenched per year. Your tiny town gets enough fresh water from the sky for 103 million people -- still impressive.
    - parimm 11y ago
      2 liters = .002 cubic meters The amazon river runs off 1300 times the drinking water of the world into the sea
      - VLM 11y ago
        Sometimes a small scale example helps, my home town of 100K people has a very small semi-navigable river pass through the middle of it, maybe a hundred feet wide and maybe head depth at most, that flows over a hundred cubic meters per second on average per wikipedia or 30K gallons per second. Some back of the envelope engineering estimates imply 30 kilogallons per second, if somehow shoved thru plumbing, equates to around or over two billion low flow toilet flushes per day. There's a lot of thirst on the west side of the Mississippi, not so much on the east. Of course water treatment to drink that river water isn't free, nor sewage treatment to keep it drinkable downstream, but still, that's a lot of water for a river. There are obvious analogies to income inequality. Humanity has more water than it knows what to do with, but simultaneously there are thirsty individuals.
- rs999gti 11y ago
  > I'm sure the time the article has been written, better and more efficient ways would turn up for churning out fresh water for public consumption. Huh? "This story appears in the September 2015 issue of Popular Mechanics."
aaronmoodie 11y ago
It's disappointing that desalinization has taken precedent over recycling water. There have been many developments in this area –including the one Bill Gates has been supporting [1] – yet despite being the more cost effective option, people can't get over the idea of drinking water that was poop. [1] http://www.gatesnotes.com/Development/Omniprocessor-From-Poop-to-Potable http://www.gatesnotes.com/Development/Omniprocessor-From-Poo...
- mapt 11y ago
  I'm a bit anxious about sewage to drinking water efforts. While I'm fairly confident that we can eliminate most live pathogenic organisms from sewage with enough work, excreted toxins, hormones, and undigested pharmaceuticals are another matter. Diluting those through a watershed serves a real purpose that sewage treatment facilities are not up to replicating.
  - RodrigoT 11y ago
    What about a grey water system? neither your toilet nor your lawn needs human consumption grade water.
    - gambiting 11y ago
      Wouldn't it be an absolutely huge cost to lay down another set of pipes for non-human drinkable water? Especially in cities.
      - eterm 11y ago
        Non-potable is the industry term for "non-human drinkable". And yes, the cost of that would be huge, not just in cities. In the UK the decision the victorians made to not have separate sewage and rain water drainage systems still has a knock-on today and costs a vast amount in water treatment, but the cost of separating rain runoff and sewage is still seen as prohibitive. edit: However, on a small local-scale grey water systems can do a lot of good, both for re-use but also rain water capture and re-use would help with flood prevention. If houses captured rainwater for use for lawn watering and other appropriate uses, this is something that could be done without great expense.
1971genocide 11y ago
Having lived in the Gulf Countries - I feel that they were ahead of the curve for some time when it came to water. When I lived in Dubai water was really expensive compared to the UK. You also never drank from the tap but bottled water. Even the culture adopted to it where people would think you were super posh if you took showers longer than 10 minutes. Also they has some interesting techniques for desalination. For example I used to live near an aluminium smelter. Apparently the heat generated due to smelting was recycled to desalinate sea water to produce water and was sold to consumers.
AdmiralAsshat 11y ago
Just glancing at the article, it struck me how similar this picture from the article is: http://pop.h-cdn.co/assets/15/35/1440426015-desalinization-2.jpg http://pop.h-cdn.co/assets/15/35/1440426015-desalinization-2... To an 1880's Ogden cigarettes card demonstrating how to make an emergency filter inside of a bucket: http://digitalcollections.nypl.org/items/510d47da-d09a-a3d9-e040-e00a18064a99 http://digitalcollections.nypl.org/items/510d47da-d09a-a3d9-... 150 years later, and the method is pretty much identical.
xutopia 11y ago
This scares me to no end. I see a future where all our water comes from bottles and we have to pay for the right to drink.
- viggity 11y ago
  It is kind of the natural conclusion when you decide to build a metropolis in a desert. Come to Iowa, our weather isn't as nice, but we've got a shit ton of water.
  - e40 11y ago
    Really? http://www.desmoinesregister.com/story/opinion/columnists/iowa-view/2015/08/24/water-works-nitrate-farm-bureau-discussion-stowe/32268923/ http://www.desmoinesregister.com/story/opinion/columnists/io... Aquifers aren't infinite.
- rs999gti 11y ago
  > we have to pay for the right to drink You already do this if you pay a local municipality for water service.
  - kardos 11y ago
    Except that the price difference is obscene [1]. A future where we are captive to bottled water purveyors control is indeed scary. [1] http://www.businessinsider.com/bottled-water-costs-2000x-more-than-tap-2013-7?IR=T http://www.businessinsider.com/bottled-water-costs-2000x-mor...
- barneygumble742 11y ago
  This is happening now in many third-world countries where it's more profitable for Pepsi and Coca Cola to sell bottled water.
- frandroid 11y ago
  Welcome to the developing world where you don't drink water coming out of the tap, even if it's chlorinated.
zer00eyz 11y ago
The fact that we CAN do this is impressive. Should we do it is another question. This is one of a host of technologies were going to have to adapt to keep the water flowing not only here in the states but across the globe. Storage, recycling, improved transit (most water systems loose 10%-30% in transport due to aging infrastructure). The reality is this is one part of a systematic change were going to have to make to keep things going.
rjv 11y ago
So this process re-introduces the brine back into the ocean, in turn making the ocean water more salty. What type of ecological ramifications does this have on the wildlife in that area?
- barneygumble742 11y ago
  That caught my attention as well. Why not send some to the east coast to de-ice in the winter?!
- elektromekatron 11y ago
  The volume of water being drawn from and the volume of evaporation, precipitation and runoff affecting that body of water, dwarf this desalination plant by an exceedingly long way.
  - mikeyouse 11y ago
    It's not the overall volume of slightly saltier water, it's the hot, concentrated brine that's damaging. Most systems are designed today such that the brine is only ~50% more salty than incoming water and only a few degrees warmer, but it's still a significant ecological issue.
- mikeyouse 11y ago
  This is pretty much the most pressing concern in any desalination effort.. Intakes and discharges are expensive in general, but to adequately dilute a brine discharge is on the order of 5x the cost of the intake system. You basically need miles of pipe into the ocean that split off like a fan in order to not significantly disrupt nearby ecosystems.
jimiray 11y ago
Or we could just stop wasting water on Factory Agriculture of Animals. http://www.cowspiracy.com/infographic/ http://www.cowspiracy.com/infographic/
timonoko 11y ago
Why do they move large amount of salt water when they could move only the sweet water? When the plant is 100 meter down, the water pressure is already the required 10 atmospheres, and when it is offshore at an ocean current the saltifying effect is a not problem. The energy needed is basically the same, but there is much less friction in the pipelines when you move only the non-pressurized end product. In my hand-cranked reverse osmosis plant the difference is 100-fold and you get good 30 minutes exercise for a cup of drinking water. If you live in a submarine, you could just turn the tap and the clean water flows in without any cranking.

75 points by prawn 11y ago

Very interesting article ... namely because fresh drinking water is now becoming a valuable resource. I'm sure the time the article has been written, better and more efficient ways would turn up for churning out fresh water for public consumption.

soft_dev_person 11y ago
I feel a very American point of view in your comment. Hasn't fresh drinking water been a valuable resource in plenty of places in the world for as long as time can remember?
- TimeToTroll 11y ago
  I'm not sure if you've heard of Africa? I don't think there's any water down there.
- nacnud 11y ago
  Not necessarily American; fresh drinking water is becoming scarcer across the world [1] and therefore even more valuable. [1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727435/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727435/
- TheSpiceIsLife 11y ago
  Two years ago I moved from South Australia to Tasmania. South Australia is known as "driest state in the driest inhabited continent in the world"[1]. Here in Tasmania there's water oozing out of the side of the hills, I'm still amazed by it. 1. http://guides.slsa.sa.gov.au/water http://guides.slsa.sa.gov.au/water Someone else has usually put it better, this time I'll draw on user adrusi: ___________ https://news.ycombinator.com/item?id=8995524 https://news.ycombinator.com/item?id=8995524 The problem with freshwater is not that the global supply is limited, rather that supplies in some high-population areas are. The Amazon river sends 209,000 cubic meters into the Atlantic every second[1]. That's 18,100,000,000 per day. A single human drinks about two liters (0.02 cubic meters) every day. There are 7 billion humans, so the global requirement is 140,000,000 cubic meters of water. The Amazon alone contains 130 times more than the global requirement for drinking water. This is domestic consumption, which comprises 10% of water usage[2]. That means that 13 times more water flows through the Amazon than all of humanity uses. That's just one river. [1]: https://en.wikipedia.org/wiki/Amazon_River https://en.wikipedia.org/wiki/Amazon_River [2]: http://www.lenntech.com/water-food-agriculture.htm http://www.lenntech.com/water-food-agriculture.htm ___________
  - soft_dev_person 11y ago
    Clearly. I was just considering the drought in the west of US lately and the statement "is now becoming". Personally I live in Norway where we wash our garbage and shower in high quality drinking water. I still find it absurd from time to time, considering the lack of fresh water in many places in the world. Edit: Corrected quote
    - Swizec 11y ago
      We've got a similar situation going on in Slovenia. I don't know if we have more fresh water than Norway, or not, but there are towns that get 3meters of rainfall per year. One such town has an area of 25km^2, that's 25,000,000 square meters. Which means that on an average year, 75,000,000 cubic meters of fresh drinkable water fall from the sky. Comparing that to stats in the grandparent post: 14 times as much drinking water falls on a tiny town in a tiny European country, as the whole world needs for drinking. That's crazy.
      - computator 11y ago
        Somewhere in your calculation there's an error. 75,000,000 cubic meters of fresh drinkable water fall from the sky per year divided by ( 0.002 cubic meters of drinking water needed per person per day x 365 days in a year ) = 103,000,000 people quenched per year. Your tiny town gets enough fresh water from the sky for 103 million people -- still impressive.
  - parimm 11y ago
    2 liters = .002 cubic meters The amazon river runs off 1300 times the drinking water of the world into the sea
    - VLM 11y ago
      Sometimes a small scale example helps, my home town of 100K people has a very small semi-navigable river pass through the middle of it, maybe a hundred feet wide and maybe head depth at most, that flows over a hundred cubic meters per second on average per wikipedia or 30K gallons per second. Some back of the envelope engineering estimates imply 30 kilogallons per second, if somehow shoved thru plumbing, equates to around or over two billion low flow toilet flushes per day. There's a lot of thirst on the west side of the Mississippi, not so much on the east. Of course water treatment to drink that river water isn't free, nor sewage treatment to keep it drinkable downstream, but still, that's a lot of water for a river. There are obvious analogies to income inequality. Humanity has more water than it knows what to do with, but simultaneously there are thirsty individuals.
rs999gti 11y ago
> I'm sure the time the article has been written, better and more efficient ways would turn up for churning out fresh water for public consumption. Huh? "This story appears in the September 2015 issue of Popular Mechanics."

aaronmoodie 11y ago

It's disappointing that desalinization has taken precedent over recycling water. There have been many developments in this area –including the one Bill Gates has been supporting [1] – yet despite being the more cost effective option, people can't get over the idea of drinking water that was poop. [1] http://www.gatesnotes.com/Development/Omniprocessor-From-Poop-to-Potable http://www.gatesnotes.com/Development/Omniprocessor-From-Poo...

mapt 11y ago
I'm a bit anxious about sewage to drinking water efforts. While I'm fairly confident that we can eliminate most live pathogenic organisms from sewage with enough work, excreted toxins, hormones, and undigested pharmaceuticals are another matter. Diluting those through a watershed serves a real purpose that sewage treatment facilities are not up to replicating.
- RodrigoT 11y ago
  What about a grey water system? neither your toilet nor your lawn needs human consumption grade water.
  - gambiting 11y ago
    Wouldn't it be an absolutely huge cost to lay down another set of pipes for non-human drinkable water? Especially in cities.
    - eterm 11y ago
      Non-potable is the industry term for "non-human drinkable". And yes, the cost of that would be huge, not just in cities. In the UK the decision the victorians made to not have separate sewage and rain water drainage systems still has a knock-on today and costs a vast amount in water treatment, but the cost of separating rain runoff and sewage is still seen as prohibitive. edit: However, on a small local-scale grey water systems can do a lot of good, both for re-use but also rain water capture and re-use would help with flood prevention. If houses captured rainwater for use for lawn watering and other appropriate uses, this is something that could be done without great expense.

1971genocide 11y ago

Having lived in the Gulf Countries - I feel that they were ahead of the curve for some time when it came to water. When I lived in Dubai water was really expensive compared to the UK. You also never drank from the tap but bottled water. Even the culture adopted to it where people would think you were super posh if you took showers longer than 10 minutes. Also they has some interesting techniques for desalination. For example I used to live near an aluminium smelter. Apparently the heat generated due to smelting was recycled to desalinate sea water to produce water and was sold to consumers.

AdmiralAsshat 11y ago

Just glancing at the article, it struck me how similar this picture from the article is: http://pop.h-cdn.co/assets/15/35/1440426015-desalinization-2.jpg http://pop.h-cdn.co/assets/15/35/1440426015-desalinization-2... To an 1880's Ogden cigarettes card demonstrating how to make an emergency filter inside of a bucket: http://digitalcollections.nypl.org/items/510d47da-d09a-a3d9-e040-e00a18064a99 http://digitalcollections.nypl.org/items/510d47da-d09a-a3d9-... 150 years later, and the method is pretty much identical.

xutopia 11y ago

This scares me to no end. I see a future where all our water comes from bottles and we have to pay for the right to drink.

viggity 11y ago
It is kind of the natural conclusion when you decide to build a metropolis in a desert. Come to Iowa, our weather isn't as nice, but we've got a shit ton of water.
- e40 11y ago
  Really? http://www.desmoinesregister.com/story/opinion/columnists/iowa-view/2015/08/24/water-works-nitrate-farm-bureau-discussion-stowe/32268923/ http://www.desmoinesregister.com/story/opinion/columnists/io... Aquifers aren't infinite.
rs999gti 11y ago
> we have to pay for the right to drink You already do this if you pay a local municipality for water service.
- kardos 11y ago
  Except that the price difference is obscene [1]. A future where we are captive to bottled water purveyors control is indeed scary. [1] http://www.businessinsider.com/bottled-water-costs-2000x-more-than-tap-2013-7?IR=T http://www.businessinsider.com/bottled-water-costs-2000x-mor...
barneygumble742 11y ago
This is happening now in many third-world countries where it's more profitable for Pepsi and Coca Cola to sell bottled water.
frandroid 11y ago
Welcome to the developing world where you don't drink water coming out of the tap, even if it's chlorinated.

zer00eyz 11y ago

The fact that we CAN do this is impressive. Should we do it is another question. This is one of a host of technologies were going to have to adapt to keep the water flowing not only here in the states but across the globe. Storage, recycling, improved transit (most water systems loose 10%-30% in transport due to aging infrastructure). The reality is this is one part of a systematic change were going to have to make to keep things going.

rjv 11y ago

So this process re-introduces the brine back into the ocean, in turn making the ocean water more salty. What type of ecological ramifications does this have on the wildlife in that area?

barneygumble742 11y ago
That caught my attention as well. Why not send some to the east coast to de-ice in the winter?!
elektromekatron 11y ago
The volume of water being drawn from and the volume of evaporation, precipitation and runoff affecting that body of water, dwarf this desalination plant by an exceedingly long way.
- mikeyouse 11y ago
  It's not the overall volume of slightly saltier water, it's the hot, concentrated brine that's damaging. Most systems are designed today such that the brine is only ~50% more salty than incoming water and only a few degrees warmer, but it's still a significant ecological issue.
mikeyouse 11y ago
This is pretty much the most pressing concern in any desalination effort.. Intakes and discharges are expensive in general, but to adequately dilute a brine discharge is on the order of 5x the cost of the intake system. You basically need miles of pipe into the ocean that split off like a fan in order to not significantly disrupt nearby ecosystems.

jimiray 11y ago

Or we could just stop wasting water on Factory Agriculture of Animals. http://www.cowspiracy.com/infographic/ http://www.cowspiracy.com/infographic/

timonoko 11y ago

Why do they move large amount of salt water when they could move only the sweet water? When the plant is 100 meter down, the water pressure is already the required 10 atmospheres, and when it is offshore at an ocean current the saltifying effect is a not problem. The energy needed is basically the same, but there is much less friction in the pipelines when you move only the non-pressurized end product. In my hand-cranked reverse osmosis plant the difference is 100-fold and you get good 30 minutes exercise for a cup of drinking water. If you live in a submarine, you could just turn the tap and the clean water flows in without any cranking.